Optical interconnections have many advantages over electric interconnections, such as a higher degree of freedom in designing, a higher transmission rate, and smaller interconnection space. Accordingly, the optical interconnections are expected to be applied to electronic devices such as super computers, high-performance servers and mobile terminals.
In an optical interconnection, a light-emitting element and a light-receiving element are optically connected to each other with an optical waveguide, a mirror and the like, for example.    Patent document 1: International Publication Pamphlet No. WO2003/041478